Along with the advancement in the computer technology, for the sake of providing more operational convenience for users, computers have been evolved from desk-top computers to notebook computers that are portable and widely accepted by the users. However, the notebook computers are still not perfect and have a significant drawback. For example, when using the notebook computer, a liquid crystal display (LCD) of the notebook computer must be deployed from a notebook main body and is usually adjusted in position by the user to a suitable view angle where text and/or pictures on the LCD can be seen. In some occasions, such as at the outdoors or in a car, there is no flat desk to support the notebook computer such that the LCD may not be positioned properly facing the user, making the notebook computer not convenient to operate.
In order to improve inconvenience in operating the notebook computer at a place having no support for the computer, a holder device 20 has been proposed in U.S. Pat. No. 5,769,369 to allow the notebook computer to be conveniently used in the car or at the outdoors. Referring to FIG. 5, the holder device 20 comprises a base member 21 on which a rail 22 and a slide 23 are provided. A stand member 24 is fixedly mounted on the slide 23. A universal ball 25 having a cradle member 26 thereon is mounted on the top of the stand member 24. A jaw 27 is mounted at each of top and bottom edges of the cradle member 26. As a result, the notebook computer 28 can be placed on the cradle member 26 and clipped by the jaws 27, such that the notebook computer 28 is stably held in position. The universal ball 25 mounted between the cradle member 26 and the stand member 24 allows arbitrary swing of the cradle member 26 to adjust an oriented angle thereof. The stand member 24 is mounted on the slide 23 such that the stand member 24 is adjusted in position by sliding the slide 23 back and forth along the rail 22. Therefore, the universal ball 25 and the slide 23 are cooperative to adjust the position and oriented angle of the cradle member 26, making the notebook computer 28 conveniently used by the user and set at a comfortable view angle for the user. This thereby eliminates the inconvenience in use due to failure to provide flat placement of the notebook computer 28.
However, besides the weight of the notebook computer 28, the holder device 20 if being taken for supporting the notebook computer 28 at the outdoors adds an additional load to the user. Therefore, in practice, the holder device 20 is usually used indoors and not for a portable application. For example, it is not convenient to bring the holder device 20 along with the notebook computer 28 everywhere the user goes, such as railroad station, cafeteria, coffee shop or conference room. The holder device 20 cannot be structurally foldable, which is also a disadvantage for portable use.
There is another conventional holder device with a stand member thereof elongated to be mounted and fixed inside a car so as to provide a small worktable for placing the notebook computer. However, such holder device is fixed in position when being in use though it allows the user to operate the notebook computer in the car, such that this holder device is not suitable for use in any location or at the outdoors without being fixed in position.
A newly developed tablet PC (personal computer) has been considered as an outstanding product to replace the notebook computer. The tablet PC is characterized in that a handwriting function and a touch panel are provided instead of keyboard and mouse for inputting data. Therefore, a display screen becomes the most important human-computer communication interface. Unlike the traditional notebook computer having the keyboard and screen connected together to form a L shape, the tablet PC is simply shaped as a flat plate, which can be placed on a desk or held by the user's hand to use.
Referring to FIG. 6, when the tablet PC 31 is to stand on the desk, a foldable supporting device 32 is required to be mounted to the back of the tablet PC 31 and deployed backwards to support the standing of the tablet PC 31 on the desk.
When the supporting device 32 is slightly unfolded, the tablet PC 31 stands substantially vertical to the desk. When the supporting device 32 is unfolded in a greater extent, the tablet PC 31 inclines backwards toward the desk. Therefore, the extent of unfolding of the supporting device 32 determines the slant angle of the table PC 31 with respect to the plane of the desk. However, positional adjustment of the tablet PC 31 limits to the unfolding direction of the supporting device 32. In case the user is changed the position thereof relative to the tablet PC 31, the whole tablet PC 31 and supporting device 32 need to be manually turned or moved to allow the display screen of the tablet PC 31 to face the user. Therefore, the supporting device 32 for supporting the standing of the tablet PC 31 is not suitable for turning of the tablet PC 31.